23-04-2023, 10:20 PM
I have quite a collection of radio-controlled clocks and watches, and have been using them for many years. They vary in features and quality.
Most of them use the MSF UK transmitter. This normally has good reception day and night. The clock usually acquires the correct time in less than 5 minutes. DCF77 reception from Germany is more difficult in the UK. The signal is usually stronger after dark; you may have to leave your clock overnight to get a signal.
Back in 2005 I built a radio-controlled nixie tube clock from a German kit. It came with a DCF77 receiver module. Unfortunately I couldn't get this to work reliably with the nixie clock. The HV power supply for the nixie tubes is quite noisy which doesn't help. So for the last 17+ years it's been running as a mains-synchronous clock. It's had over 150,000 hours of use and the nixies are still good! The mains frequency varies throughout the day, so the clock may gain or lose up to 30 seconds or so, but this drift is corrected periodically by the electricity company so over the long term it's more accurate than most quartz clocks.
Talking of quartz clocks and watches, most of them have used a single 1.5v battery since the 1970s when mass-produced ones first started to appear. Accuracy is typically +/- 1 second per day. The best ones I've got are about 1 minute per year; some as bad as 10-20 seconds per day. An annoying number of digital watches seem to run slightly too fast, yet the time cannot be adjusted backwards. Whose idea was that?
Radio-controlled LCD clocks and watches usually have an indication on the display to show that a signal is being received. Analogue wall clocks usually don't. Sometimes your clock can't get a good signal where you've placed it. You may have no way of knowing this. I have occasionally had R-C clocks and watches do strange things, like go exactly 1 minute slow, or even show a completely random time. It's rare but be aware that it can happen, maybe due to interference. Surprisingly when this has happened to me, only one of the clocks in the same room was affected.
As I said, there's variation in quality and features. I have a Lidl weather station with radio-controlled clock. Perhaps not surprisingly this defaults to a location in Germany and CET when the batteries are first inserted. It's possible to change it to UK time and location but it's a bit fiddly. The procedure is in the instruction manual. Likewise I have a Casio Wave Ceptor watch that can receive a choice of several different time transmitters around the world. Your exact time zone can be set too. Battery life is surprisingly good - several years life from a lithium button cell. To save battery power, the analogue part does not have a moving seconds hand. The minute hand only moves once every 20 seconds. The MSF wall clocks often have no means of setting the time manually. If you're in a different time zone or can't get a signal, you're out of luck. My Acctim LCD MSF clock has a GMT/CET switch on the back, but that appears to be the only option.
Yes, there are other devices that can auto-set the time by other means (FM RDS, DAB, DTT, Internet). All of these have their pros and cons. And of course they will only work as long as the transmission is maintained. Bad luck to those in Ireland who lost their DAB signal. At least nearly all DAB radios can receive FM broacasts, and some but not all can set the time from FM RDS. I have heard there was some software for Apple mobile phones that could generate the 60KHz signals used by radio-controlled clocks, thus providing another way to auto-set them in case things change in the future. Of course the mobile phone is likely to be obsolete long before then!
On the whole, I like radio-controlled clocks in their various forms. Not having to keep re-setting them is a real boon!
Most of them use the MSF UK transmitter. This normally has good reception day and night. The clock usually acquires the correct time in less than 5 minutes. DCF77 reception from Germany is more difficult in the UK. The signal is usually stronger after dark; you may have to leave your clock overnight to get a signal.
Back in 2005 I built a radio-controlled nixie tube clock from a German kit. It came with a DCF77 receiver module. Unfortunately I couldn't get this to work reliably with the nixie clock. The HV power supply for the nixie tubes is quite noisy which doesn't help. So for the last 17+ years it's been running as a mains-synchronous clock. It's had over 150,000 hours of use and the nixies are still good! The mains frequency varies throughout the day, so the clock may gain or lose up to 30 seconds or so, but this drift is corrected periodically by the electricity company so over the long term it's more accurate than most quartz clocks.
Talking of quartz clocks and watches, most of them have used a single 1.5v battery since the 1970s when mass-produced ones first started to appear. Accuracy is typically +/- 1 second per day. The best ones I've got are about 1 minute per year; some as bad as 10-20 seconds per day. An annoying number of digital watches seem to run slightly too fast, yet the time cannot be adjusted backwards. Whose idea was that?
Radio-controlled LCD clocks and watches usually have an indication on the display to show that a signal is being received. Analogue wall clocks usually don't. Sometimes your clock can't get a good signal where you've placed it. You may have no way of knowing this. I have occasionally had R-C clocks and watches do strange things, like go exactly 1 minute slow, or even show a completely random time. It's rare but be aware that it can happen, maybe due to interference. Surprisingly when this has happened to me, only one of the clocks in the same room was affected.
As I said, there's variation in quality and features. I have a Lidl weather station with radio-controlled clock. Perhaps not surprisingly this defaults to a location in Germany and CET when the batteries are first inserted. It's possible to change it to UK time and location but it's a bit fiddly. The procedure is in the instruction manual. Likewise I have a Casio Wave Ceptor watch that can receive a choice of several different time transmitters around the world. Your exact time zone can be set too. Battery life is surprisingly good - several years life from a lithium button cell. To save battery power, the analogue part does not have a moving seconds hand. The minute hand only moves once every 20 seconds. The MSF wall clocks often have no means of setting the time manually. If you're in a different time zone or can't get a signal, you're out of luck. My Acctim LCD MSF clock has a GMT/CET switch on the back, but that appears to be the only option.
Yes, there are other devices that can auto-set the time by other means (FM RDS, DAB, DTT, Internet). All of these have their pros and cons. And of course they will only work as long as the transmission is maintained. Bad luck to those in Ireland who lost their DAB signal. At least nearly all DAB radios can receive FM broacasts, and some but not all can set the time from FM RDS. I have heard there was some software for Apple mobile phones that could generate the 60KHz signals used by radio-controlled clocks, thus providing another way to auto-set them in case things change in the future. Of course the mobile phone is likely to be obsolete long before then!
On the whole, I like radio-controlled clocks in their various forms. Not having to keep re-setting them is a real boon!
